Prosecutors yesterday gathered more evidence against a New Jersey couple accused of starving their adopted sons.

Investigators from the Camden County prosecutor’s office converged on the two-story Collingswood house, carrying tools and kits past the yellow ribbons placed on the front stairs last week by family friends.

After several hours inside the hours they left with a number of trash bags, but declined to comment on the contents.

The visit marked the second time in less than a week that county officers searched the house where Raymond and Vanessa Jackson lived with their biological and adopted children.

On Tuesday, investigators brought out several bags and boxes, as well as a windowsill that sources said was pocked with bite marks.

Police and prosecutors would not comment yesterday on what they were looking for or on what was taken out during either search. But a source said they were looking for evidence of intent.

Earlier in the day, the owner of the house, John Andrews, tried to enter the Jackson home, but was turned away by investigators.

Federal lawmakers also have joined the investigation.

The congressional House Ways and Means Subcommittee on Human Resources will hold a hearing Thursday on the case, the subcommittee chairman has announced.

“It is hard to imagine how adults could intentionally starve children,” said Rep. Wally Herger (R-Calif.). “It is also hard to accept the grim reality that we, as taxpayers, subsidized their terrible neglect to the tune of tens of thousands of dollars.”

Local and state officials, as well as experts familiar with the case, are expected to testify.

A spokeswoman for the state Department of Human Services said an official from the department would attend.With Post Wire Services